This invention relates to electronic assemblies and more particularly to an assembly system and technique which greatly simplifies assembly, testing and configuration control for some kinds of electronic assembly packages.
There are electronic instrumentation assemblies in which a signal representing a certain variable condition is processed preparatory to forwarding the processed signal to a control system or a display device and wherein such assemblies are produced in significant volume and used for a number of different applications or installations. In many cases the different applications require only slight variations among the units produced, yet this variation requires that the units be separately designed, assembled, tested, calibrated and given separate part numbers. One example of such units is a signal conditioning device which receives input signals from piezoelectric vibration sensors in gas turbine engines and provides such signals to the cockpit of an aircraft to inform the pilot or flight engineer of the fact of engine vibration in excess of a desired amplitude and also the time the engine is exposed to such vibration. This information may be used to determine when an engine requires major servicing or overhauling.
Such instrumentation assemblies have been in use for many years. In accordance with the prior art the assembly for each engine was different; in some cases the assemblies for the same engines used on different aircraft were different. Each had a different part number, and was built, tested and calibrated differently. In the case of aircraft used for carrying passengers, the Federal Aviation Authority requires certain configuration controls which are applicable to each part number. Since some airlines have several types of aircraft and engines, this has led to complicated and involved servicing procedures.